<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>两栏布局_flex</title>
</head>
<style>
    .outer{
        height: 800px;
        display: flex;
    }

    .left{
        height:100%;
        width:500px;
        background-color:gray;
    }

    .right{
        height:100%;
        background-color:pink;
        flex:1;
    }
</style>
<body>
    <div class="outer">
        <div class="left"></div>
        <div class="right"></div>
    </div>
</body>
</html>